num_derive/
lib.rs

1// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2// file at the top-level directory of this distribution and at
3// http://rust-lang.org/COPYRIGHT.
4//
5// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8// option. This file may not be copied, modified, or distributed
9// except according to those terms.
10
11#![crate_type = "proc-macro"]
12#![doc(html_root_url = "https://docs.rs/num-derive/0.3")]
13#![recursion_limit = "512"]
14
15//! Procedural macros to derive numeric traits in Rust.
16//!
17//! ## Usage
18//!
19//! Add this to your `Cargo.toml`:
20//!
21//! ```toml
22//! [dependencies]
23//! num-traits = "0.2"
24//! num-derive = "0.3"
25//! ```
26//!
27//! Then you can derive traits on your own types:
28//!
29//! ```rust
30//! #[macro_use]
31//! extern crate num_derive;
32//!
33//! #[derive(FromPrimitive, ToPrimitive)]
34//! enum Color {
35//!     Red,
36//!     Blue,
37//!     Green,
38//! }
39//! # fn main() {}
40//! ```
41//!
42//! ## Explicit import
43//!
44//! By default the `num_derive` procedural macros assume that the
45//! `num_traits` crate is a direct dependency. If `num_traits` is instead
46//! a transitive dependency, the `num_traits` helper attribute can be
47//! used to tell `num_derive` to use a specific identifier for its imports.
48//!
49//! ```rust
50//! #[macro_use]
51//! extern crate num_derive;
52//! // Lets pretend this is a transitive dependency from another crate
53//! // reexported as `some_other_ident`.
54//! extern crate num_traits as some_other_ident;
55//!
56//! #[derive(FromPrimitive, ToPrimitive)]
57//! #[num_traits = "some_other_ident"]
58//! enum Color {
59//!     Red,
60//!     Blue,
61//!     Green,
62//! }
63//! # fn main() {}
64//! ```
65
66extern crate proc_macro;
67
68use proc_macro::TokenStream;
69use proc_macro2::{Span, TokenStream as TokenStream2};
70use quote::quote;
71use syn::{Data, Fields, Ident};
72
73/// Try to parse the tokens, or else return a compilation error
74macro_rules! parse {
75    ($tokens:ident as $type:ty) => {
76        match syn::parse::<$type>($tokens) {
77            Ok(parsed) => parsed,
78            Err(error) => {
79                return TokenStream::from(error.to_compile_error());
80            }
81        }
82    };
83}
84
85// Within `exp`, you can bring things into scope with `extern crate`.
86//
87// We don't want to assume that `num_traits::` is in scope - the user may have imported it under a
88// different name, or may have imported it in a non-toplevel module (common when putting impls
89// behind a feature gate).
90//
91// Solution: let's just generate `extern crate num_traits as _num_traits` and then refer to
92// `_num_traits` in the derived code.  However, macros are not allowed to produce `extern crate`
93// statements at the toplevel.
94//
95// Solution: let's generate `mod _impl_foo` and import num_traits within that.  However, now we
96// lose access to private members of the surrounding module.  This is a problem if, for example,
97// we're deriving for a newtype, where the inner type is defined in the same module, but not
98// exported.
99//
100// Solution: use the anonymous const trick.  For some reason, `extern crate` statements are allowed
101// here, but everything from the surrounding module is in scope.  This trick is taken from serde.
102fn anon_const_trick(exp: TokenStream2) -> TokenStream2 {
103    quote! {
104        #[allow(non_upper_case_globals, unused_qualifications)]
105        const _: () = {
106            #[allow(clippy::useless_attribute)]
107            #[allow(rust_2018_idioms)]
108            extern crate num_traits as _num_traits;
109            #exp
110        };
111    }
112}
113
114// If `data` is a newtype, return the type it's wrapping.
115fn newtype_inner(data: &syn::Data) -> Option<syn::Type> {
116    match *data {
117        Data::Struct(ref s) => {
118            match s.fields {
119                Fields::Unnamed(ref fs) => {
120                    if fs.unnamed.len() == 1 {
121                        Some(fs.unnamed[0].ty.clone())
122                    } else {
123                        None
124                    }
125                }
126                Fields::Named(ref fs) => {
127                    if fs.named.len() == 1 {
128                        panic!("num-derive doesn't know how to handle newtypes with named fields yet. \
129                           Please use a tuple-style newtype, or submit a PR!");
130                    }
131                    None
132                }
133                _ => None,
134            }
135        }
136        _ => None,
137    }
138}
139
140struct NumTraits {
141    import: Ident,
142    explicit: bool,
143}
144
145impl quote::ToTokens for NumTraits {
146    fn to_tokens(&self, tokens: &mut TokenStream2) {
147        self.import.to_tokens(tokens);
148    }
149}
150
151impl NumTraits {
152    fn new(ast: &syn::DeriveInput) -> Self {
153        // If there is a `num_traits` MetaNameValue attribute on the input,
154        // retrieve its value, and use it to create an `Ident` to be used
155        // to import the `num_traits` crate.
156        for attr in &ast.attrs {
157            if attr.path().is_ident("num_traits") {
158                if let Ok(syn::MetaNameValue {
159                    value:
160                        syn::Expr::Lit(syn::ExprLit {
161                            lit: syn::Lit::Str(ref lit_str),
162                            ..
163                        }),
164                    ..
165                }) = attr.meta.require_name_value()
166                {
167                    return NumTraits {
168                        import: syn::Ident::new(&lit_str.value(), lit_str.span()),
169                        explicit: true,
170                    };
171                } else {
172                    panic!("#[num_traits] attribute value must be a str");
173                }
174            }
175        }
176
177        // Otherwise, we'll implicitly import our own.
178        NumTraits {
179            import: Ident::new("_num_traits", Span::call_site()),
180            explicit: false,
181        }
182    }
183
184    fn wrap(&self, output: TokenStream2) -> TokenStream2 {
185        if self.explicit {
186            output
187        } else {
188            anon_const_trick(output)
189        }
190    }
191}
192
193/// Derives [`num_traits::FromPrimitive`][from] for simple enums and newtypes.
194///
195/// [from]: https://docs.rs/num-traits/0.2/num_traits/cast/trait.FromPrimitive.html
196///
197/// # Examples
198///
199/// Simple enums can be derived:
200///
201/// ```rust
202/// # #[macro_use]
203/// # extern crate num_derive;
204///
205/// #[derive(FromPrimitive)]
206/// enum Color {
207///     Red,
208///     Blue,
209///     Green = 42,
210/// }
211/// # fn main() {}
212/// ```
213///
214/// Enums that contain data are not allowed:
215///
216/// ```compile_fail
217/// # #[macro_use]
218/// # extern crate num_derive;
219///
220/// #[derive(FromPrimitive)]
221/// enum Color {
222///     Rgb(u8, u8, u8),
223///     Hsv(u8, u8, u8),
224/// }
225/// # fn main() {}
226/// ```
227///
228/// Structs are not allowed:
229///
230/// ```compile_fail
231/// # #[macro_use]
232/// # extern crate num_derive;
233/// #[derive(FromPrimitive)]
234/// struct Color {
235///     r: u8,
236///     g: u8,
237///     b: u8,
238/// }
239/// # fn main() {}
240/// ```
241#[proc_macro_derive(FromPrimitive, attributes(num_traits))]
242pub fn from_primitive(input: TokenStream) -> TokenStream {
243    let ast = parse!(input as syn::DeriveInput);
244    let name = &ast.ident;
245
246    let import = NumTraits::new(&ast);
247
248    let impl_ = if let Some(inner_ty) = newtype_inner(&ast.data) {
249        quote! {
250            impl #import::FromPrimitive for #name {
251                #[inline]
252                fn from_i64(n: i64) -> ::core::option::Option<Self> {
253                    <#inner_ty as #import::FromPrimitive>::from_i64(n).map(#name)
254                }
255                #[inline]
256                fn from_u64(n: u64) -> ::core::option::Option<Self> {
257                    <#inner_ty as #import::FromPrimitive>::from_u64(n).map(#name)
258                }
259                #[inline]
260                fn from_isize(n: isize) -> ::core::option::Option<Self> {
261                    <#inner_ty as #import::FromPrimitive>::from_isize(n).map(#name)
262                }
263                #[inline]
264                fn from_i8(n: i8) -> ::core::option::Option<Self> {
265                    <#inner_ty as #import::FromPrimitive>::from_i8(n).map(#name)
266                }
267                #[inline]
268                fn from_i16(n: i16) -> ::core::option::Option<Self> {
269                    <#inner_ty as #import::FromPrimitive>::from_i16(n).map(#name)
270                }
271                #[inline]
272                fn from_i32(n: i32) -> ::core::option::Option<Self> {
273                    <#inner_ty as #import::FromPrimitive>::from_i32(n).map(#name)
274                }
275                #[inline]
276                fn from_i128(n: i128) -> ::core::option::Option<Self> {
277                    <#inner_ty as #import::FromPrimitive>::from_i128(n).map(#name)
278                }
279                #[inline]
280                fn from_usize(n: usize) -> ::core::option::Option<Self> {
281                    <#inner_ty as #import::FromPrimitive>::from_usize(n).map(#name)
282                }
283                #[inline]
284                fn from_u8(n: u8) -> ::core::option::Option<Self> {
285                    <#inner_ty as #import::FromPrimitive>::from_u8(n).map(#name)
286                }
287                #[inline]
288                fn from_u16(n: u16) -> ::core::option::Option<Self> {
289                    <#inner_ty as #import::FromPrimitive>::from_u16(n).map(#name)
290                }
291                #[inline]
292                fn from_u32(n: u32) -> ::core::option::Option<Self> {
293                    <#inner_ty as #import::FromPrimitive>::from_u32(n).map(#name)
294                }
295                #[inline]
296                fn from_u128(n: u128) -> ::core::option::Option<Self> {
297                    <#inner_ty as #import::FromPrimitive>::from_u128(n).map(#name)
298                }
299                #[inline]
300                fn from_f32(n: f32) -> ::core::option::Option<Self> {
301                    <#inner_ty as #import::FromPrimitive>::from_f32(n).map(#name)
302                }
303                #[inline]
304                fn from_f64(n: f64) -> ::core::option::Option<Self> {
305                    <#inner_ty as #import::FromPrimitive>::from_f64(n).map(#name)
306                }
307            }
308        }
309    } else {
310        let variants = match ast.data {
311            Data::Enum(ref data_enum) => &data_enum.variants,
312            _ => panic!(
313                "`FromPrimitive` can be applied only to enums and newtypes, {} is neither",
314                name
315            ),
316        };
317
318        let from_i64_var = quote! { n };
319        let clauses: Vec<_> = variants
320            .iter()
321            .map(|variant| {
322                let ident = &variant.ident;
323                match variant.fields {
324                    Fields::Unit => (),
325                    _ => panic!(
326                        "`FromPrimitive` can be applied only to unitary enums and newtypes, \
327                         {}::{} is either struct or tuple",
328                        name, ident
329                    ),
330                }
331
332                quote! {
333                    if #from_i64_var == #name::#ident as i64 {
334                        ::core::option::Option::Some(#name::#ident)
335                    }
336                }
337            })
338            .collect();
339
340        let from_i64_var = if clauses.is_empty() {
341            quote!(_)
342        } else {
343            from_i64_var
344        };
345
346        quote! {
347            impl #import::FromPrimitive for #name {
348                #[allow(trivial_numeric_casts)]
349                #[inline]
350                fn from_i64(#from_i64_var: i64) -> ::core::option::Option<Self> {
351                    #(#clauses else)* {
352                        ::core::option::Option::None
353                    }
354                }
355
356                #[inline]
357                fn from_u64(n: u64) -> ::core::option::Option<Self> {
358                    Self::from_i64(n as i64)
359                }
360            }
361        }
362    };
363
364    import.wrap(impl_).into()
365}
366
367/// Derives [`num_traits::ToPrimitive`][to] for simple enums and newtypes.
368///
369/// [to]: https://docs.rs/num-traits/0.2/num_traits/cast/trait.ToPrimitive.html
370///
371/// # Examples
372///
373/// Simple enums can be derived:
374///
375/// ```rust
376/// # #[macro_use]
377/// # extern crate num_derive;
378///
379/// #[derive(ToPrimitive)]
380/// enum Color {
381///     Red,
382///     Blue,
383///     Green = 42,
384/// }
385/// # fn main() {}
386/// ```
387///
388/// Enums that contain data are not allowed:
389///
390/// ```compile_fail
391/// # #[macro_use]
392/// # extern crate num_derive;
393///
394/// #[derive(ToPrimitive)]
395/// enum Color {
396///     Rgb(u8, u8, u8),
397///     Hsv(u8, u8, u8),
398/// }
399/// # fn main() {}
400/// ```
401///
402/// Structs are not allowed:
403///
404/// ```compile_fail
405/// # #[macro_use]
406/// # extern crate num_derive;
407/// #[derive(ToPrimitive)]
408/// struct Color {
409///     r: u8,
410///     g: u8,
411///     b: u8,
412/// }
413/// # fn main() {}
414/// ```
415#[proc_macro_derive(ToPrimitive, attributes(num_traits))]
416pub fn to_primitive(input: TokenStream) -> TokenStream {
417    let ast = parse!(input as syn::DeriveInput);
418    let name = &ast.ident;
419
420    let import = NumTraits::new(&ast);
421
422    let impl_ = if let Some(inner_ty) = newtype_inner(&ast.data) {
423        quote! {
424            impl #import::ToPrimitive for #name {
425                #[inline]
426                fn to_i64(&self) -> ::core::option::Option<i64> {
427                    <#inner_ty as #import::ToPrimitive>::to_i64(&self.0)
428                }
429                #[inline]
430                fn to_u64(&self) -> ::core::option::Option<u64> {
431                    <#inner_ty as #import::ToPrimitive>::to_u64(&self.0)
432                }
433                #[inline]
434                fn to_isize(&self) -> ::core::option::Option<isize> {
435                    <#inner_ty as #import::ToPrimitive>::to_isize(&self.0)
436                }
437                #[inline]
438                fn to_i8(&self) -> ::core::option::Option<i8> {
439                    <#inner_ty as #import::ToPrimitive>::to_i8(&self.0)
440                }
441                #[inline]
442                fn to_i16(&self) -> ::core::option::Option<i16> {
443                    <#inner_ty as #import::ToPrimitive>::to_i16(&self.0)
444                }
445                #[inline]
446                fn to_i32(&self) -> ::core::option::Option<i32> {
447                    <#inner_ty as #import::ToPrimitive>::to_i32(&self.0)
448                }
449                #[inline]
450                fn to_i128(&self) -> ::core::option::Option<i128> {
451                    <#inner_ty as #import::ToPrimitive>::to_i128(&self.0)
452                }
453                #[inline]
454                fn to_usize(&self) -> ::core::option::Option<usize> {
455                    <#inner_ty as #import::ToPrimitive>::to_usize(&self.0)
456                }
457                #[inline]
458                fn to_u8(&self) -> ::core::option::Option<u8> {
459                    <#inner_ty as #import::ToPrimitive>::to_u8(&self.0)
460                }
461                #[inline]
462                fn to_u16(&self) -> ::core::option::Option<u16> {
463                    <#inner_ty as #import::ToPrimitive>::to_u16(&self.0)
464                }
465                #[inline]
466                fn to_u32(&self) -> ::core::option::Option<u32> {
467                    <#inner_ty as #import::ToPrimitive>::to_u32(&self.0)
468                }
469                #[inline]
470                fn to_u128(&self) -> ::core::option::Option<u128> {
471                    <#inner_ty as #import::ToPrimitive>::to_u128(&self.0)
472                }
473                #[inline]
474                fn to_f32(&self) -> ::core::option::Option<f32> {
475                    <#inner_ty as #import::ToPrimitive>::to_f32(&self.0)
476                }
477                #[inline]
478                fn to_f64(&self) -> ::core::option::Option<f64> {
479                    <#inner_ty as #import::ToPrimitive>::to_f64(&self.0)
480                }
481            }
482        }
483    } else {
484        let variants = match ast.data {
485            Data::Enum(ref data_enum) => &data_enum.variants,
486            _ => panic!(
487                "`ToPrimitive` can be applied only to enums and newtypes, {} is neither",
488                name
489            ),
490        };
491
492        let variants: Vec<_> = variants
493            .iter()
494            .map(|variant| {
495                let ident = &variant.ident;
496                match variant.fields {
497                    Fields::Unit => (),
498                    _ => {
499                        panic!("`ToPrimitive` can be applied only to unitary enums and newtypes, {}::{} is either struct or tuple", name, ident)
500                    },
501                }
502
503                // NB: We have to check each variant individually, because we'll only have `&self`
504                // for the input.  We can't move from that, and it might not be `Clone` or `Copy`.
505                // (Otherwise we could just do `*self as i64` without a `match` at all.)
506                quote!(#name::#ident => #name::#ident as i64)
507            })
508            .collect();
509
510        let match_expr = if variants.is_empty() {
511            // No variants found, so do not use Some to not to trigger `unreachable_code` lint
512            quote! {
513                match *self {}
514            }
515        } else {
516            quote! {
517                ::core::option::Option::Some(match *self {
518                    #(#variants,)*
519                })
520            }
521        };
522
523        quote! {
524            impl #import::ToPrimitive for #name {
525                #[inline]
526                #[allow(trivial_numeric_casts)]
527                fn to_i64(&self) -> ::core::option::Option<i64> {
528                    #match_expr
529                }
530
531                #[inline]
532                fn to_u64(&self) -> ::core::option::Option<u64> {
533                    self.to_i64().map(|x| x as u64)
534                }
535            }
536        }
537    };
538
539    import.wrap(impl_).into()
540}
541
542const NEWTYPE_ONLY: &str = "This trait can only be derived for newtypes";
543
544/// Derives [`num_traits::NumOps`][num_ops] for newtypes.  The inner type must already implement
545/// `NumOps`.
546///
547/// [num_ops]: https://docs.rs/num-traits/0.2/num_traits/trait.NumOps.html
548///
549/// Note that, since `NumOps` is really a trait alias for `Add + Sub + Mul + Div + Rem`, this macro
550/// generates impls for _those_ traits.  Furthermore, in all generated impls, `RHS=Self` and
551/// `Output=Self`.
552#[proc_macro_derive(NumOps)]
553pub fn num_ops(input: TokenStream) -> TokenStream {
554    let ast = parse!(input as syn::DeriveInput);
555    let name = &ast.ident;
556    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
557    let impl_ = quote! {
558        impl ::core::ops::Add for #name {
559            type Output = Self;
560            #[inline]
561            fn add(self, other: Self) -> Self {
562                #name(<#inner_ty as ::core::ops::Add>::add(self.0, other.0))
563            }
564        }
565        impl ::core::ops::Sub for #name {
566            type Output = Self;
567            #[inline]
568            fn sub(self, other: Self) -> Self {
569                #name(<#inner_ty as ::core::ops::Sub>::sub(self.0, other.0))
570            }
571        }
572        impl ::core::ops::Mul for #name {
573            type Output = Self;
574            #[inline]
575            fn mul(self, other: Self) -> Self {
576                #name(<#inner_ty as ::core::ops::Mul>::mul(self.0, other.0))
577            }
578        }
579        impl ::core::ops::Div for #name {
580            type Output = Self;
581            #[inline]
582            fn div(self, other: Self) -> Self {
583                #name(<#inner_ty as ::core::ops::Div>::div(self.0, other.0))
584            }
585        }
586        impl ::core::ops::Rem for #name {
587            type Output = Self;
588            #[inline]
589            fn rem(self, other: Self) -> Self {
590                #name(<#inner_ty as ::core::ops::Rem>::rem(self.0, other.0))
591            }
592        }
593    };
594    impl_.into()
595}
596
597/// Derives [`num_traits::NumCast`][num_cast] for newtypes.  The inner type must already implement
598/// `NumCast`.
599///
600/// [num_cast]: https://docs.rs/num-traits/0.2/num_traits/cast/trait.NumCast.html
601#[proc_macro_derive(NumCast, attributes(num_traits))]
602pub fn num_cast(input: TokenStream) -> TokenStream {
603    let ast = parse!(input as syn::DeriveInput);
604    let name = &ast.ident;
605    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
606
607    let import = NumTraits::new(&ast);
608
609    let impl_ = quote! {
610        impl #import::NumCast for #name {
611            #[inline]
612            fn from<T: #import::ToPrimitive>(n: T) -> ::core::option::Option<Self> {
613                <#inner_ty as #import::NumCast>::from(n).map(#name)
614            }
615        }
616    };
617
618    import.wrap(impl_).into()
619}
620
621/// Derives [`num_traits::Zero`][zero] for newtypes.  The inner type must already implement `Zero`.
622///
623/// [zero]: https://docs.rs/num-traits/0.2/num_traits/identities/trait.Zero.html
624#[proc_macro_derive(Zero, attributes(num_traits))]
625pub fn zero(input: TokenStream) -> TokenStream {
626    let ast = parse!(input as syn::DeriveInput);
627    let name = &ast.ident;
628    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
629
630    let import = NumTraits::new(&ast);
631
632    let impl_ = quote! {
633        impl #import::Zero for #name {
634            #[inline]
635            fn zero() -> Self {
636                #name(<#inner_ty as #import::Zero>::zero())
637            }
638            #[inline]
639            fn is_zero(&self) -> bool {
640                <#inner_ty as #import::Zero>::is_zero(&self.0)
641            }
642        }
643    };
644
645    import.wrap(impl_).into()
646}
647
648/// Derives [`num_traits::One`][one] for newtypes.  The inner type must already implement `One`.
649///
650/// [one]: https://docs.rs/num-traits/0.2/num_traits/identities/trait.One.html
651#[proc_macro_derive(One, attributes(num_traits))]
652pub fn one(input: TokenStream) -> TokenStream {
653    let ast = parse!(input as syn::DeriveInput);
654    let name = &ast.ident;
655    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
656
657    let import = NumTraits::new(&ast);
658
659    let impl_ = quote! {
660        impl #import::One for #name {
661            #[inline]
662            fn one() -> Self {
663                #name(<#inner_ty as #import::One>::one())
664            }
665            #[inline]
666            fn is_one(&self) -> bool {
667                <#inner_ty as #import::One>::is_one(&self.0)
668            }
669        }
670    };
671
672    import.wrap(impl_).into()
673}
674
675/// Derives [`num_traits::Num`][num] for newtypes.  The inner type must already implement `Num`.
676///
677/// [num]: https://docs.rs/num-traits/0.2/num_traits/trait.Num.html
678#[proc_macro_derive(Num, attributes(num_traits))]
679pub fn num(input: TokenStream) -> TokenStream {
680    let ast = parse!(input as syn::DeriveInput);
681    let name = &ast.ident;
682    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
683
684    let import = NumTraits::new(&ast);
685
686    let impl_ = quote! {
687        impl #import::Num for #name {
688            type FromStrRadixErr = <#inner_ty as #import::Num>::FromStrRadixErr;
689            #[inline]
690            fn from_str_radix(s: &str, radix: u32) -> ::core::result::Result<Self, Self::FromStrRadixErr> {
691                <#inner_ty as #import::Num>::from_str_radix(s, radix).map(#name)
692            }
693        }
694    };
695
696    import.wrap(impl_).into()
697}
698
699/// Derives [`num_traits::Float`][float] for newtypes.  The inner type must already implement
700/// `Float`.
701///
702/// [float]: https://docs.rs/num-traits/0.2/num_traits/float/trait.Float.html
703#[proc_macro_derive(Float, attributes(num_traits))]
704pub fn float(input: TokenStream) -> TokenStream {
705    let ast = parse!(input as syn::DeriveInput);
706    let name = &ast.ident;
707    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
708
709    let import = NumTraits::new(&ast);
710
711    let impl_ = quote! {
712        impl #import::Float for #name {
713            #[inline]
714            fn nan() -> Self {
715                #name(<#inner_ty as #import::Float>::nan())
716            }
717            #[inline]
718            fn infinity() -> Self {
719                #name(<#inner_ty as #import::Float>::infinity())
720            }
721            #[inline]
722            fn neg_infinity() -> Self {
723                #name(<#inner_ty as #import::Float>::neg_infinity())
724            }
725            #[inline]
726            fn neg_zero() -> Self {
727                #name(<#inner_ty as #import::Float>::neg_zero())
728            }
729            #[inline]
730            fn min_value() -> Self {
731                #name(<#inner_ty as #import::Float>::min_value())
732            }
733            #[inline]
734            fn min_positive_value() -> Self {
735                #name(<#inner_ty as #import::Float>::min_positive_value())
736            }
737            #[inline]
738            fn max_value() -> Self {
739                #name(<#inner_ty as #import::Float>::max_value())
740            }
741            #[inline]
742            fn is_nan(self) -> bool {
743                <#inner_ty as #import::Float>::is_nan(self.0)
744            }
745            #[inline]
746            fn is_infinite(self) -> bool {
747                <#inner_ty as #import::Float>::is_infinite(self.0)
748            }
749            #[inline]
750            fn is_finite(self) -> bool {
751                <#inner_ty as #import::Float>::is_finite(self.0)
752            }
753            #[inline]
754            fn is_normal(self) -> bool {
755                <#inner_ty as #import::Float>::is_normal(self.0)
756            }
757            #[inline]
758            fn classify(self) -> ::core::num::FpCategory {
759                <#inner_ty as #import::Float>::classify(self.0)
760            }
761            #[inline]
762            fn floor(self) -> Self {
763                #name(<#inner_ty as #import::Float>::floor(self.0))
764            }
765            #[inline]
766            fn ceil(self) -> Self {
767                #name(<#inner_ty as #import::Float>::ceil(self.0))
768            }
769            #[inline]
770            fn round(self) -> Self {
771                #name(<#inner_ty as #import::Float>::round(self.0))
772            }
773            #[inline]
774            fn trunc(self) -> Self {
775                #name(<#inner_ty as #import::Float>::trunc(self.0))
776            }
777            #[inline]
778            fn fract(self) -> Self {
779                #name(<#inner_ty as #import::Float>::fract(self.0))
780            }
781            #[inline]
782            fn abs(self) -> Self {
783                #name(<#inner_ty as #import::Float>::abs(self.0))
784            }
785            #[inline]
786            fn signum(self) -> Self {
787                #name(<#inner_ty as #import::Float>::signum(self.0))
788            }
789            #[inline]
790            fn is_sign_positive(self) -> bool {
791                <#inner_ty as #import::Float>::is_sign_positive(self.0)
792            }
793            #[inline]
794            fn is_sign_negative(self) -> bool {
795                <#inner_ty as #import::Float>::is_sign_negative(self.0)
796            }
797            #[inline]
798            fn mul_add(self, a: Self, b: Self) -> Self {
799                #name(<#inner_ty as #import::Float>::mul_add(self.0, a.0, b.0))
800            }
801            #[inline]
802            fn recip(self) -> Self {
803                #name(<#inner_ty as #import::Float>::recip(self.0))
804            }
805            #[inline]
806            fn powi(self, n: i32) -> Self {
807                #name(<#inner_ty as #import::Float>::powi(self.0, n))
808            }
809            #[inline]
810            fn powf(self, n: Self) -> Self {
811                #name(<#inner_ty as #import::Float>::powf(self.0, n.0))
812            }
813            #[inline]
814            fn sqrt(self) -> Self {
815                #name(<#inner_ty as #import::Float>::sqrt(self.0))
816            }
817            #[inline]
818            fn exp(self) -> Self {
819                #name(<#inner_ty as #import::Float>::exp(self.0))
820            }
821            #[inline]
822            fn exp2(self) -> Self {
823                #name(<#inner_ty as #import::Float>::exp2(self.0))
824            }
825            #[inline]
826            fn ln(self) -> Self {
827                #name(<#inner_ty as #import::Float>::ln(self.0))
828            }
829            #[inline]
830            fn log(self, base: Self) -> Self {
831                #name(<#inner_ty as #import::Float>::log(self.0, base.0))
832            }
833            #[inline]
834            fn log2(self) -> Self {
835                #name(<#inner_ty as #import::Float>::log2(self.0))
836            }
837            #[inline]
838            fn log10(self) -> Self {
839                #name(<#inner_ty as #import::Float>::log10(self.0))
840            }
841            #[inline]
842            fn max(self, other: Self) -> Self {
843                #name(<#inner_ty as #import::Float>::max(self.0, other.0))
844            }
845            #[inline]
846            fn min(self, other: Self) -> Self {
847                #name(<#inner_ty as #import::Float>::min(self.0, other.0))
848            }
849            #[inline]
850            fn abs_sub(self, other: Self) -> Self {
851                #name(<#inner_ty as #import::Float>::abs_sub(self.0, other.0))
852            }
853            #[inline]
854            fn cbrt(self) -> Self {
855                #name(<#inner_ty as #import::Float>::cbrt(self.0))
856            }
857            #[inline]
858            fn hypot(self, other: Self) -> Self {
859                #name(<#inner_ty as #import::Float>::hypot(self.0, other.0))
860            }
861            #[inline]
862            fn sin(self) -> Self {
863                #name(<#inner_ty as #import::Float>::sin(self.0))
864            }
865            #[inline]
866            fn cos(self) -> Self {
867                #name(<#inner_ty as #import::Float>::cos(self.0))
868            }
869            #[inline]
870            fn tan(self) -> Self {
871                #name(<#inner_ty as #import::Float>::tan(self.0))
872            }
873            #[inline]
874            fn asin(self) -> Self {
875                #name(<#inner_ty as #import::Float>::asin(self.0))
876            }
877            #[inline]
878            fn acos(self) -> Self {
879                #name(<#inner_ty as #import::Float>::acos(self.0))
880            }
881            #[inline]
882            fn atan(self) -> Self {
883                #name(<#inner_ty as #import::Float>::atan(self.0))
884            }
885            #[inline]
886            fn atan2(self, other: Self) -> Self {
887                #name(<#inner_ty as #import::Float>::atan2(self.0, other.0))
888            }
889            #[inline]
890            fn sin_cos(self) -> (Self, Self) {
891                let (x, y) = <#inner_ty as #import::Float>::sin_cos(self.0);
892                (#name(x), #name(y))
893            }
894            #[inline]
895            fn exp_m1(self) -> Self {
896                #name(<#inner_ty as #import::Float>::exp_m1(self.0))
897            }
898            #[inline]
899            fn ln_1p(self) -> Self {
900                #name(<#inner_ty as #import::Float>::ln_1p(self.0))
901            }
902            #[inline]
903            fn sinh(self) -> Self {
904                #name(<#inner_ty as #import::Float>::sinh(self.0))
905            }
906            #[inline]
907            fn cosh(self) -> Self {
908                #name(<#inner_ty as #import::Float>::cosh(self.0))
909            }
910            #[inline]
911            fn tanh(self) -> Self {
912                #name(<#inner_ty as #import::Float>::tanh(self.0))
913            }
914            #[inline]
915            fn asinh(self) -> Self {
916                #name(<#inner_ty as #import::Float>::asinh(self.0))
917            }
918            #[inline]
919            fn acosh(self) -> Self {
920                #name(<#inner_ty as #import::Float>::acosh(self.0))
921            }
922            #[inline]
923            fn atanh(self) -> Self {
924                #name(<#inner_ty as #import::Float>::atanh(self.0))
925            }
926            #[inline]
927            fn integer_decode(self) -> (u64, i16, i8) {
928                <#inner_ty as #import::Float>::integer_decode(self.0)
929            }
930            #[inline]
931            fn epsilon() -> Self {
932                #name(<#inner_ty as #import::Float>::epsilon())
933            }
934            #[inline]
935            fn to_degrees(self) -> Self {
936                #name(<#inner_ty as #import::Float>::to_degrees(self.0))
937            }
938            #[inline]
939            fn to_radians(self) -> Self {
940                #name(<#inner_ty as #import::Float>::to_radians(self.0))
941            }
942        }
943    };
944
945    import.wrap(impl_).into()
946}
947
948/// Derives [`num_traits::Signed`][signed] for newtypes.  The inner type must already implement
949/// `Signed`.
950///
951/// [signed]: https://docs.rs/num-traits/0.2/num_traits/sign/trait.Signed.html
952#[proc_macro_derive(Signed, attributes(num_traits))]
953pub fn signed(input: TokenStream) -> TokenStream {
954    let ast = parse!(input as syn::DeriveInput);
955    let name = &ast.ident;
956    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
957
958    let import = NumTraits::new(&ast);
959
960    let impl_ = quote! {
961        impl #import::Signed for #name {
962            #[inline]
963            fn abs(&self) -> Self {
964                #name(<#inner_ty as #import::Signed>::abs(&self.0))
965            }
966            #[inline]
967            fn abs_sub(&self, other: &Self) -> Self {
968                #name(<#inner_ty as #import::Signed>::abs_sub(&self.0, &other.0))
969            }
970            #[inline]
971            fn signum(&self) -> Self {
972                #name(<#inner_ty as #import::Signed>::signum(&self.0))
973            }
974            #[inline]
975            fn is_positive(&self) -> bool {
976                <#inner_ty as #import::Signed>::is_positive(&self.0)
977            }
978            #[inline]
979            fn is_negative(&self) -> bool {
980                <#inner_ty as #import::Signed>::is_negative(&self.0)
981            }
982        }
983    };
984
985    import.wrap(impl_).into()
986}
987
988/// Derives [`num_traits::Unsigned`][unsigned].  The inner type must already implement
989/// `Unsigned`.
990///
991/// [unsigned]: https://docs.rs/num/latest/num/traits/trait.Unsigned.html
992#[proc_macro_derive(Unsigned, attributes(num_traits))]
993pub fn unsigned(input: TokenStream) -> TokenStream {
994    let ast = parse!(input as syn::DeriveInput);
995    let name = &ast.ident;
996
997    let import = NumTraits::new(&ast);
998
999    let impl_ = quote! {
1000        impl #import::Unsigned for #name {}
1001    };
1002
1003    import.wrap(impl_).into()
1004}
num_derive/lib.rs

num_derive/
lib.rs
